1. Field of the Invention
The invention relates to a muffler for the exhaust of a machine.
2. Background Information
Mufflers are generally disposed in the end region of exhaust gas conduits which discharge the gases leaving the exhaust of a machine (engine, pump or the like) into the open.
The following problem exists, for example, in connection with rotary vacuum pumps:
Rotary vacuum pumps include single shaft (sliding vane rotary pumps, rotary piston pumps, or the like) and dual shaft pumps (pumps equipped with pairs of rotors of the screw, Roots, or claw type, or the like) which additionally may be constructed to have one or several stages. In order to improve the suction capability of such pumps, it is possible to increase their number of revolutions. However, this also causes a considerable increase in noise development. In particular, dry running dual shaft vacuum pumps (suction chamber without oil) generate very high noise pressure levels in the region of their exhausts.
Vacuum pumps of the above-mentioned type are frequently employed in chemical or other processes (etching, vapor deposition processes, or the like). The gases sucked in by the vacuum pump in these cases are generally damaging to the environment. The exhaust of the vacuum pump is therefore connected to a permanently installed exhaust gas conduit which discharges the conveyed gases through gas washers or other cleaning systems into the open air. The gases extracted, in particular, from etching and vapor deposition processes are additionally often heavily laden with dust. Since in such processes it is customary to employ dry-running vacuum pumps, there exists the problem of dust deposits, particularly in the discharge region of the pump and in the connected exhaust gas conduits.